Speedometer



Feb. 17, 1931. w, Mom-:LL 1,793,120

SPEEDOMETER Filed Nov. 12, 1928 Welders mn @0W/ if an im Patented Feb. 17, 1931 UNITED STATES PATENT OFFICE SPEIEDOMETER Application led November 12, 1928, Serial No.

My invention'relates to speedometers in which a plurality of gearings, each correspending to a definite range of measurements, are provided and arranged to be rendered operative as desired.

lt is an object of my invention to improve a speedometer of this type. To this end I provide a change-speed gear and means rotatably carried on the speedometer casing for throwing in the gear-ings corresponding to the several ranges of measurements or speeds of1 the change-speed gear, by rotating sucht means.

Heretofore the change from onespeed to another was effected byV axial displacement..

By providing a change-speed gear as 'described, and bychanging the rspeeds through the medium of a rotary part,the size of t e instrument is reduced and its operation, maintenance and manufacture are simplified and facilitated. i

ln a preferred embodiment of my invention the driving shaft is supported eccentrically in a` cap which conceals the gears of the change-speed gear, and a pinion is secured on the driving shaft within the cap. By rotating the cap the pinion is alternately placed in operat-ive relation to the several sets of wheels constituting the change-speed gear. ln the drawing affixed to this specification and forming a part thereof a hand-speed ometer emboyding my invention is illustrated diagrannnatically by way of example:

lln the drawing Fig. l is an end elevation. and l Fig. 2 is a side elevation, the parts in which the gearing is housed being shown in section, Figs. 3 and 4 are sections on the lines A-B and C-l) in Fig. 1, respectively.

yReferring to the drawing, 3 is the foundation plate of the instrument on which the several parts constituting the speedometer unit are mounted. These parts need not be described in ldetail as they are of the usual design.

4 is the main shaft of the instrument, 1 is a pinion on the main shaft and 8, 9 and 10 are gears which are in permanent mesh with the pinion 1 on the vmain shaft ,4. 13, v14: and 15 are gears on shafts 5, 6 and 7. respectively, the

318,728, and in Germany November 15, 1927.

shafts being carried in the foundation plate 3 and the parallel plate 3a which is connected with the plate 3 by stays 3b. 11 is a cap which is rotatably carried on the plates 3 and 3a, 12 is a soldered sleeve, connecting the cap 55 11 with the casing of the instrument, and 16 C is a driving shaft which is eccentrically supported in a boss of the cap 11, the parallel plate 3a being centrally recessed for the reception of the boss. ,2 is a pinion on the inner end of shaft 1 which is adapted to alternately engage the gears 13, lll and 15 upon rotation of the cap 11.

l't will'be understood that upon rotation of the cap 11 the pinion 2 is bodily rotated on a circular path at a tangent to the pitch circles of the wheels 13, 14 and 15. Consequently, upon rotating the cap 11, the pinion 2 will be placed in mesh with one of the gears 13, 14 and .15, as desired, and it is possible to set the speedometer for the desired range of measurements, or speed of the changespeed gear, on the shortest way by rotating the cap 1l' to the left or to the right, as required.

The instrument does not require for its operation any other means beside the cap 11 and the gearings which would be required in any case, and is readily manufactured as the cap 11 and the means by which it is held on the instrument, are simple rotary elements.

The length of the novel speedometer is only about two thirds, as compared with the instruments referred to in the introduction, in which the range of measurements is varied by axial displacement.

It is to be understood that l am not limited to a change-speed gear having three speeds as described but that l may provide any number of speeds.

l wish it to be understood that I do not desire to be limited to the exact details of construction shown and described for obvious modifications will occur to a person skilled in the art.

1n the claim aliixed to this specification no selection of any particular modification of the invention isintended to the exclusion of other modifications thereof and the right to subsequentlymake claim to any modication .not covered-by this claim is expressly re.-y

` iliary plate spaced apart from, and connected with, said principal plate, a gearing organization including a plurality of lay shafts,

one shaft per range, supported in said princi- 'r pal and auxiliary plates, a pair of gear Wheels l on each lay shaft, one gear wheel in each pair meshing permanently with the pinion on said principalshatfa casing mounted to rotate about the axis ofsaid principal shaft and surrounding said gearing organization, a

driving shafty mounted to rotate in said'casing eccentrically with respect to the axis of said principal shaft, and a pinion on said driving shaft adapted to be moved into mesh with those gear wheelson said lay shafts which are not permanent mesh with the pinion on said principal shaft, as said casing isv rotated vabout the axis of said principal shaft. l

In testimony yvhereof I aix ling si ature. 

